Developing intelligent transportation systems which take into consideration the economical, environmental, and safety factors of the modern society, is one of the main challenges of this century. Progress in the fields of mobile robots, control architectures, advanced technologies, and computer vision allows us to now envisage the integration of autonomous and driving-assistance capabilities within future moving vehicle s. Research concerning the development of self contained unmanned moving vehicles is currently being carried out on a very active scale. The existing types of unmanned moving vehicles are designed so that the travel sections thereof are equipped with wheels crawlers etc and in which the travel motion is accomplished under the control of a control section.
Smart environments represent the next evolutionary development step in industries such as construction, manufacturing, transportation systems and even in sporting goods equipment. Like any functioning organism, the smart environment relies first and foremost on sensory data from the real world. Sensory data comes from multiple sensors of different modalities in distributed locations. The smart environment needs information about all of its surroundings as well as about its internal workings.
The challenge is determining the prioritized hierarchy of: (1) detecting the relevant quantities, (2) monitoring and collecting the data, (3) assessing and evaluating the information, and (4) performing decision-making actions. The information needed by smart environments is provided by Distributed Sensor Systems, which are responsible for sensing as well as for the first stages of the processing hierarchy.
The drive to minimize human interaction in transportation vehicles is stronger than ever, especially in public transportation, automobiles, and etc. For instant, just a few years ago, automobiles seldom had very sophisticated safety systems. Now, it is rare to find an automobile without various safety and protection systems. And now new technology is evolving to the point of being able to offer preventive methods to better manage and dissipate sudden impact energy to the vehicle.
The use of radars in collision avoidance systems is generally known. U.S. Pat. No. 4,403,220 dated Sep. 6, 1983 discloses a radar system adapted to detect relative headings between aircraft or ships at sea and a detected object moving relative to the ground. The system is adapted to collision avoidance application. U.S. Pat. No. 4,072,945 dated Feb. 7, 1978 discloses a radar-operated collision avoidance system for roadway vehicles. The system senses the vehicle speed relative to an object and its distance and decides whether the vehicle is approaching the object at a dangerously high speed. A minimum allowable distance represented by a digital code is stored in a memory of a computer and the minimum allowable distance is compared with the distance sensed by the radar. U.S. Pat. No. 4,626,850 dated Dec. 2, 1986 discloses a dual operational mode vehicle detection and collision avoidance apparatus using a single active or passive ultrasonic ranging device. The system is particularly adapted to scan the rear and the lateral sides of the motor vehicle to warn the vehicle user of any danger when changing lanes.
Most of the prior art collision avoidance systems use microwave radars as the ranging and detecting device. There are multiple problems of these automobile collision avoidance systems when microwave radars are used. One major issue is related to the beam width that is the angular width of the main lobe of the radar, and the associated angular resolution of the microwave radar. The beam width is inversely proportional to the antenna diameter in wavelength. With the limitation of the antenna size, it is very difficult to make reasonable size microwave radar with beam width less than 3 degrees. At the desired scanning distance, this beam width will scan an area which is much too big and thus is too nonspecific and difficult to differentiate the received echoes. Besides getting echo from another car in front of it, this radar will also receive echoes from roadside signs, trees or posts, or bridges over passing an expressway. On highways with divided lanes the microwave radar will receive echoes from cars 2 or 3 lanes away and has difficulty in differentiating them from echoes coming from objects in the same lane. Because of the poor angular resolution of microwave radars, the direction of objects cannot be specifically determined and objects too close to one another cannot be separated. The angular resolution of microwave radars is not small enough for them to be effectively used to monitor roadway traffic. The other issue is that the microwave radars have difficulty in distinguishing radar signals coming from adjacent cars with similar equipment. If there are more than two cars with the same radar equipment on the same scene, the signals become very confusing.
The ultrasonic ranging and detecting device's angular resolution is also too poor to be effectively used in roadway traffic monitoring. The ultrasonic devices have even more problems than the microwave radars in determining the direction and location of echoes precisely, in the detection of directional change of objects and in avoiding signals coming from adjacent vehicles with similar equipment
Systems and devices for collision avoidance of air, sea and ground vehicles are in general well known. Early devices utilized forward looking antennae with radio frequency transmitters and receivers. In U.S. Pat. No. 3,891,966 Sytankay disclosed a laser system designed to avoid rear end collisions between automobiles. This apparatus provides a laser transmitting and receiving system and a detection system mounted on the front and rear of automobiles. The transmitter at the front end emits a signal having a designated wavelength f1 and the receiver at the front end receives signals having a designated wavelength f2. Upon reception of signals of wavelength f1 the modulator at the rear end of a leading car would activate the transmitter which would send a return signal of wavelength f2 to the receiver at the front end of the trailing car. This signal is interpreted by circuits in the receiver and furnishes a warning of the proximity of the vehicles.
Sterzer et al in U.S. Pat. No. 4,003,049 shows a frequency modulated continuous wave collision avoidance radar responsive to both reply signals from cooperating tagged targets and to skin reflections from proximate non cooperating non tagged targets. German Patent No 2,327,186 and U.S. Pat. No. 4,101,888 to Heller et al describe a system in which detections are limited to the electronic road channel in which the vehicle is traveling. The radar has two antennas which radiate RF signals of different frequencies. The signals received by one of the two antennas are evaluated by determining the difference between the amplitudes of the RF signals reflected from an object. A signal proportional to the difference is then compared to a threshold proportional to a predetermined azimuth range so that cars moving in the same road lane may by discriminated against other passing objects.
More recent devices employ a millimeter wave antenna capable of electronic scanning. An example is shown in U.S. Pat. No. 5,264,859 to Lee et al in which a linear ferrite loaded slot array illuminates a dielectric lens. Beam scanning is achieved by controlling a bias magnetic field along the ferrite rod of the slot array. More advanced systems might employ a conformal array disposed within or around car structures such as bumpers. Such antenna systems are generally taught by Special in U.S. Pat. No. 5,512,906. A more complete total avoidance system is discussed by Shaw et al in U.S. Pat. No. 5,314,037. Here the laser detection system is coupled to both warning and automatic car control devises such as steering and braking systems in order to take evasive action. Obviously such complex systems are expensive to build and will have a lower inherent reliability. Although the above systems may find utility in avoiding front and rear collisions they are not adapted for early warning of imminent side collisions.
The above techniques and solution can also be applied for flying objects or any moving equipment such as drones, flying cars, robots, and in general moving equipment and flying equipments.
One effective and novel ways of minimizing collision and maximizing safety is to monitor the environment and to predict the impact using distributed sensors. Distributed sensors estimate and calculate environmental parameters related to external objects. Therefore, as shown in FIG. 1 the information collected by wireless sensors and other type of sensors such as image sensors, heat sensors, speed sensors, acceleration sensors, ultrasonic sensors, proximity sensors, pressure sensors, G sensors, and IR (infrared) sensors could be used for a variety of applications. One application is to help navigation of the vehicle and minimizes driver interference or even facilitates vehicle navigation without a driver. Another application is to provide warning for driver of the vehicle. The collected information could also be used to activate certain devices like expandable pads, airbags, or compressed air before an impact occurs. This feature can be used both internal and external to the moving vehicle. The airbags or expandable pads can be mounted on external body of vehicle and activated before the impact to absorb the force of impact for both protection of vehicle and its passengers. The wireless sensors collect the required information in presence of other vehicles which are equipped with the same technology. This requires establishment of a standard for wireless sensors used for vehicles application so that all vehicles use the same technology. This way every moving or flying vehicle/object can be assigned a unique identification address similar to an IP (Internet Protocol) address to be used by wireless sensor installed at its different body location. In other words every moving vehicle/objects or flying vehicle/objects is assigned an IP (Internet Protocol) address similar to an IP communication networks. The IP address can be used internally to communicate with central controller of moving or flying object/vehicle The IP address can also be used to communicate with external communication networks such as cellular wireless network (5G and beyond) or private and proprietary network. The signal that wireless sensor uses to monitor its surrounding environment is based on moving or flying vehicle/object IP address. By applying this technique and additional algorithm any interference between wireless sensors used in all moving or flying objects/vehicles present in near vicinity can easily be avoided and usable information gathered in timely manner.
To complement the environment information obtain by a wireless sensor an image sensor may be used. The image sensor uses the images from environment to identify various objects in the environment and obtain essential parameters. To increase the accuracy of the parameters the image sensor is calibrated extensively for various objects in a typical environment. The calibration data and pixels from environment images obtained by image sensor are used to monitor the environment.
For flying objects two of possible protection gears are airbag and compressed gas systems. Airbags have evolved with regards to design, fabric and the components that go into making it. Compressed gas (air) systems are in nearly most industrial facilities around the world.
Compressed air is air kept under a pressure that is greater than atmospheric pressure. In industry, compressed air is so widely used that it is often regarded as the fourth utility, after electricity, natural gas and water. However, compressed air is more expensive than the other three utilities when evaluated on a per unit energy delivered basis. Compressed air is used for many purposes, including:
Railway breaking system: A railway air brake is a railway brake power braking system with compressed air as the operating medium.
Road vehicle breaking system: An air brake or, more formally, a compressed air brake system, is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle.
Air guns: An air gun is any kind of small arms that propels projectiles by means of mechanically pressurized compressed air or other gas (shooting involves no chemical reaction), in contrast to explosive propellant of a firearm.
An airbag is made up of three parts. The first part is the bag itself that is made out of thin nylon fabric and is folded in the steering wheel or the dashboard of a car. The second part of the airbag is the sensor that informs the bag to inflate when the car meets with an accident. The sensor detects the collision force and calculates the force equal to running into a brick wall at around 10 to 15 miles per hour. The third part consists of an inflation system.
The airbags are inflated using sodium azide and potassium nitrate. When any collision takes place, the sensor detects the collision force and informs the bag to inflate. At that time, the sodium azide and potassium nitrate react quickly and produces a large pulse of hot nitrogen gas. The gas inflates the bag in turn and the bag literally bursts out of the steering wheel or the dash board. After a second, the bag starts deflating with the help of the holes present on it to get out of your way.
When an airbag is used for protection and is activated before impact it is highly likely that a single layer airbag bursts and does not provide the required protection. Therefore, there is a need for redundancy in case the airbag due to force of impact bursts. Redundancy may be achieved by having nested airbags or multilayer airbags.
Expandable pad can also be used for moving vehicle/object and it is made of polymers that can be expanded by applying voltage to two ends of the pad. The pad after activation may need to be replaced.